#include <cstdio>
#include <cmath>
#define PI 3.1415926535

using namespace std;

class Circle
{
    public:
        Circle(double _r=0)
        {
            setByR(_r);
        }

        Circle(const Circle& circle)
        {
            r = circle.r;
            c = circle.c;
            s = circle.s;
        }

        void setByR(double _r)
        {
            r = _r;
            c = 2 * PI * _r;
            s = PI * _r * _r;
        }

        void setByC(double _c)
        {
            setByR(_c / PI / 2);
        }

        void setByS(double _s)
        {
            setByR(sqrt(_s / PI));
        }

        double getR()
        {
            return r;
        }

        double getC()
        {
            return c;
        }

        double getS()
        {
            return s;
        }
    
    private:
        double r, c, s;
};

void print_circle_info(Circle circle)
{
    printf("R = %.2lf   C = %.2lf   S = %.2lf\n", circle.getR(), circle.getC(), circle.getS());
}

int main()
{
    double tmp;

    printf("Input R: ");
    scanf("%lf", &tmp);
    Circle circle1(tmp);
    print_circle_info(circle1);

    printf("Input C: ");
    scanf("%lf", &tmp);
    Circle circle2;
    circle2.setByC(tmp);
    print_circle_info(circle2);

    printf("Input S: ");
    scanf("%lf", &tmp);
    Circle circle3;
    circle3.setByS(tmp);
    print_circle_info(circle3);

    return 0;
}
